Zeolites are crystalline aluminosilicate compositions which are microporous and which are formed from corner sharing AlO2 and SiO2 tetrahedra. Numerous zeolites, both naturally occurring and synthetically prepared are used in various industrial processes. Synthetic zeolites are prepared via hydrothermal synthesis employing suitable sources of Si, Al, as well as structure directing agents such as alkali metals, alkaline earth metals, amines, or organoammonium cations. The structure directing agents reside in the pores of the zeolite and are largely responsible for the particular structure that is ultimately formed. These species balance the framework charge associated with aluminum and can also serve as space fillers. Zeolites are characterized by having pore openings of uniform dimensions, having a significant ion exchange capacity, and being capable of reversibly desorbing an adsorbed phase which is dispersed throughout the internal voids of the crystal without significantly displacing any atoms which make up the permanent zeolite crystal structure. Zeolites can be used as catalysts for hydrocarbon conversions, which can take place on outside surfaces as well as on internal surfaces within the pore.
One such hydrocarbon conversion process includes the catalytic monoalkylation of benzene with propylene to produce isopropylbenzene (cumene) using the zeolitic catalyst designated UZM-8. While the primary product is isopropylbenzene, quantities of polyalkylated benzene variants are also produced in small quantities. These polyalkylated variants can be recovered via fractionation and trans-alkylation but are undesirable due to the additional utility cost and yield loss during the trans-alkylation process. As such, technology to increase the selectivity of the catalytic alkylation to isopropylbenzene over the polyalkylated variants is desired.